Discussions are under way in the Basque region of Spain to form a new coalition government following Sunday's election.
Juan Jose Ibarretxe (centre) had hoped for bigger poll success
The ruling moderate Basque nationalists won more votes than any other party, but failed to gain an overall majority.
The BBC correspondent in Madrid says it is not going to be easy for the nationalists to find partners.
Co-operation with the Socialists could mean giving up plans for independence, whereas joining hardline nationalists could damage the party's reputation.
Batasuna, the political wing of the armed separatist group, Eta, was banned from taking part in the elections.
Call for change
The ruling moderate coalition, led by the Nationalist Basque Party's Juan Jose Ibarretxe, won 29 of the 75 seats, gaining just over 38% of the vote.
It lost four seats it won in 2001 elections, while candidates endorsed by Batasuna won a surprise nine seats.
The newly-formed Communist Party of Basque Lands, or Ehak, came fourth in the polls.
The BBC's Katya Adler in Madrid says the party appears to have mopped up the votes of supporters of the outlawed Batasuna party.
Mr Ibarretxe's party had hoped that a strong showing in the elections would force the Spanish government to negotiate on a referendum on greater autonomy and the right to break away from Spain.
The little-known Ehak party won a surprise number of seats
The secretary general of the Basque Nationalist Party (PNV), Josune Aristondo, said all the main political parties in the Basque country, with the exception of the conservatives, agreed there had been a call for change.
"Our main aim is to enter a new phase of peace and political co-existence in the Basque country - the rest will follow," he said.
His party wants to see the introduction of Basque citizenship, an independent judiciary, penal system and direct representation at European Union meetings.
The Spanish parliament earlier this year rejected the plan, which Mr Ibarretxe says is the only way to stop Basque separatist violence.